The present invention relates to a system for maintaining and distributing sheets of photosensitive film within a laser imager. More particularly, it relates to a system configured to receive and open a cartridge of photosensitive film within an imager, and separate and deliver individual sheets of photosensitive film from the cartridge to a film transport system of the imager.
Light sensitive, photothermographic film is used in many applications ranging from a standard photocopying apparatus, to graphic arts and/or medical imaging/recording printing systems. For example, in the medical industry, laser imaging systems employing photothermographic film are commonly used to produce photographic images from digital image data generated by magnetic resonance (MR), computer tomography (CT) or other types of scanners. Systems of this type typically include a laser imager for exposing an image on the photothermographic film, a thermofilm processor for developing the film through the application of heat, and an image management subsystem for coordinating the operation of the laser imager and the thermofilm processor. The resulting image is available for diagnostic use by medical radiologists and communications to referring physicians and their patients.
Generally speaking, a photosensitive film laser imager includes a film supply system, a film exposure assembly, a film processing station (or developer), a film dispensing area and a film transport system. Each of these components are associated within a relatively large imager housing.
Sheets of unexposed photosensitive film is normally stacked in a sealed, standardized film cartridge, for delivery to the imager. The standard film cartridge includes 125 sheets of film and is sealed by a foil cover. During use, the film cartridge is inserted into the film supply system of the imager. The film supply system normally includes mechanisms for unsealing the film cartridge and subsequently removing individual sheets of film. In this regard, the film supply system separates and delivers an individual sheet of photosensitive film from the film cartridge to the film transport system. The film transport system, in turn, delivers the individual sheet of film to the film exposure assembly. Within the film exposure assembly, photographic images are exposed on the film from image data (e.g., digital or analog) using a laser imager. The exposed sheet of film is then transported, via the film transport system, to the film processing station where the film is developed. After thermal processing, the film is cooled and transported to the film dispensing area where the final image is available to the user.
While the above-described laser imager has proven to be highly successful, several potential drawbacks may exist. For example, the film supply system is normally very complex, and therefore expensive. The film supply system is generally configured to define a film cartridge insertion path which is approximately in the direction of the plane generated by the path in which individual sheets of film are removed from the cartridge within the imager housing. In other words, the film cartridge is inserted, either horizontally or vertically, into the imager housing in the same direction that the sheets of film are subsequently removed from the film cartridge. However, when a film jam invariably occurs, film jam removal requires user access to the film supply system from a plane normal to the film path. Thus, the imager housing must provide user access from at least two sides of the machine, thereby increasing costs. Additionally, the film cartridge is normally maintained by the film supply system in a horizontal, rather than angled, position. This horizontal positioning requires an enlarged, and therefore more expensive, housing to accommodate a full length of the film cartridge.
In addition to the concerns associated with film cartridge positioning, a standard film supply system also generally includes an intricate, multi-component mechanism for separating and delivering individual sheets of film to the film transport system. The film supply system must be designed to ensure that only a single sheet of photosensitive film is delivered to the film transport system. In particular, it is understood that an interface force develops between sheets of photosensitive film otherwise stored within a sealed cartridge. The interface force can include static charge, edge burrs, and suction forces, and causes two or more sheets of photosensitive film to stick to one another. Obviously, a system error may result if more than a single sheet of film is mistakenly forwarded to the film exposure assembly. Thus, the film supply system must be designed to consistently separate individual sheets of film from one another.
To accomplish desired film separation, the standard film supply system normally includes several mechanisms and a number of independently driven parts which maneuver the film sheet in different directions to effectuate film separation. This complex approach to separating and delivering sheets of film is normally quite expensive.
The known laser imager provides a device able to rapidly and consistently produce laser images of high quality. However, the design of the film supply system within the imager, including cartridge insertion and film pick-up, is complex and relatively expensive. Therefore, a substantial need exists for a film supply system configured to meet the design and operational constraints of a photosensitive film laser imager, in a cost-effective manner.